1. Field of the Invention
The present invention relates to a lighting device for an elevator, and more particularly, to an improvement in such a lighting device adapted to be installed in an elevator car.
2. Description of the Prior Art
In general, passengers in an elevator car often feel uneasy or stifled due to the close quarters of the car which is in fact a narrow and closed chamber. In particular, such uneasy feelings will be amplified by the discomfort of being in an elevator installed in one of the super-multistoried buildings, or when one is in an elevator travelling for a relatively long duration, or of being in an elevator car full of passengers. It is, therefore, highly desirable to improve such situations.
On the ceiling of an elevator car which has the greatest influence on the closeness of the car, however, a simple lighting device with monotonous lighting effects alone has hitherto been installed.
The construction of such a conventional lighting device will now be described with reference to FIG. 16. An elevator car 1 has a ceiling panel 2 to which a reflection panel 3 formed of metal having a mirror on the surface of the side facing the car interior is attached. A plurality of light sources 4 such as, for example, small electric lamps, fluorescent lamps or the like are mounted on the reflection panel 3 at locations uniformly distributed thereover so that a part of the light emitted from the respective light sources 4 are reflected by the reflection panel 3 to merge with the remaining portion of the light which directly emit from the light sources 4 into the interior of the car 1 so as to inhance the luminance therein. FIG. 17 illustrates the details in cross section of an example of the light source 4 in the form of a small electric lamp mounted on the reflection panel 3.
Accordingly, when passengers in the elevator car 1 look at the conventional lighting device on the ceiling panel 2 in the car 1, they can see the interior of the car 1 reflected in the mirror surface of the reflection panel 3 and the light sources 4 in the form of dispersed small electric lamps also reflected in a dispersed pattern in the reflection panel 3 as illustrated by broken line 4a in FIG. 16. In this case, the light intensity of the light sources 4 is generally determined such that a predetermined luminance can be obtained in the car 1. In other words, the light intensity of the light sources 4 is actually determined from a practical point of view such that passengers in the elevator car 1 can visually discern objects therein.
With the conventional lighting device for an elevator car as constructed in the above manner, the plurality of light sources 4 such as small electric lamps are arranged in a dispersed pattern, and the light beams emitted from the respective light sources 4 are reflected by the reflection panel 3 which is formed of metal and the inner surface of which has a mirror or hairline finish. In addition, the light from the light sources 4, being white light with no change in color, is not appealing to passenger's eyes. Under these circumstances, it is desirable to develop a lighting device which can produce an illumination with color variations.
In addition, in the event that such light sources 4 as electric incandescent lamps employing filaments are used, the light sources are point light sources which have the respective filaments therein and which are narrow in their light-emitting areas. Likewise, imaginary light sources reflected in the metal reflection panel 3, being also point light sources, have narrow light-emitting areas, respectively. As a result, for the purpose of enabling the entire area of the car ceiling to achieve an effective illumination, it is necessary to employ a great number of electric lamps which are to be arranged in a dispersed pattern over the whole ceiling surface. This results in the problem of high production costs.